Abstract: In this research paper, the effect of four wave mixing (FWM) has been analyzed and compared for different channel allocation schemes such as equal space channel allocation (ESCA) and unequal space channel allocation (USCA) schemes for a Dense Wavelength Division Multiplexing (DWDM) system. The simulated results have been analyzed for fixed numbers of channels (N=8). We have evaluated the Quality-factor (Q-factor) of the DWDM system for different parameters such as optical fiber length, laser power, channel spacing and data rates. In the ESCA and USCA schemes, the Q-factor varies from 27.72 dB to 5.95 dB and from 40.47 dB to 6.25 dB respectively as the distance increases from 25Km to 125 Km at a bit rate of 810 Gbps. The results of simulative observation revealed that the unequal channel spacing provided better Q-factor for DWDM system than equal space channel allocation scheme Further, it has been observed that on decreasing the channel spacing between input channels, their mutual interference increases and thus, the effect of four wave mixing also increases. Similarly, as the channel spacing increases, the FWM effect decreases for the DWDM system.

Keywords: FWM, ESCA, USCA, DWDM system, Channel spacing, Q-factor.